Skewing spoils table and bed linen
Customers prefer bed linen and table linen that is square or rectangular rather than diamond-shaped.
The correct shape is generally achieved by placing the leading edge onto the feed bands exactly at right angles to the direction of travel through the ironer. When linen is fed automatically, this is easily achieved by setting up the feeder correctly and most laundry engineers are adept at doing so.
However, when work is fed manually the operator is responsible for getting the angle right. Poorly trained operators will often misfeed so make sure that staff know how to lay the fabric down correctly every time.
Pay careful attention to the bed coverage and ironer speed `– there is no point in running an ironer faster than operators can feed the linen. If the ironer is run at 40m/minute but with only 40% bed coverage then halving the speed to achieve 90% coverage will improve both the result and productivity.
The solution here is to check the bed coverage and if operators are not consistently keeping the gap between items to a minimum reduce the linear speed until minimum gaps can be maintained. Operators will now be able to achieve a square leading edge much more easily and with increased output and no misfeeds.
Avoiding wine glass creasing
Rows of small semi-circular creases running across sheets, often referred to as “wine glass” creases,spoil the finish but also indicate that the ironer’s roll-to-bed fit is poor.
These “wine glass” creases are usually caused by an over-sized roll which is struggling both to fit into the bed and also to accommodate the thickness of the sheet being processed.
The ironer should have been supplied with a set of girthing tapes, each one made of metal with two grooves carved into it. The appropriate tape is fitted round the roll to which it relates and if the diameter is correct, the grooves will line up to within 1 – 2mm. In some ironers the rolls will all be the same size and only one girthing tape is needed. Some have different diameters for each roll and need separate tapes for each. Some girthing tapes are cut to exactly the correct circumference, so then it is the ends of the tapes which must line up.
Many rolls are slightly oversized when they have just been re-clothed but after bedding in and cutting back the clothing overlap, they need to be exactly the right size. The calender clothing supplier can help as the company will have a range of thicknesses and techniques to give exactly the final diameter required. Modern calender clothing technology is moving to two turns of thicker, stronger material to improve the clothing porosity and hence the drying rate.
Correcting the roll size prevents wine glass creasing. The leading edge will go into the in-running nip much more smoothly, producing a consistently better result.
Bed and table linen gradually distorts
Polycotton is once again becoming a commonly used fabric in the textile rental business and this has led to problems of distortion.
Large rental plants now often operate their ironers at 10bar steam pressure to get the best performance out of an expensive investment in modern equipment. The temperature of 10bar saturated steam is 184C which is above the softening point of some polyester fibres.
When fabric is stretched in the machine direction as it passes through a multi-roll ironer this produces a better crease-free finish as the taut fabric is heated over the gaps between the rolls. However, at metal temperatures above 180C the polyester will soften and stay deformed when stretched.
As a result the linen gets progressively longer in one direction each time it is ironed and this may go unnoticed for a time, perhaps as long as six months. It is only when the sheet no longer fits the hotel bed or the duvet pokes out of its cover that the customer complains.
If the area of the distorted sheet is compared with that of a new one, it will be found that total shrinkage across the whole area is only 5 – 6%, which is quite normal and commercially acceptable. However, the linen’s shape will be very different after it has been washed and ironed several times.
If it has been ironed conventionally, selvedge-first, then the sheet will be up to 12% shorter and 15% wider than its original dimensions.
The solution is to take ironing into account when ordering linen and specify the size so that after stretching on the ironer, the pieces come out with the right dimensions and shape.
Diamond creases in folded table cloths
Restaurant managers, are becoming more critical of the finish on table linen and more demanding in the quality they will accept.
They may complain if the cloth has fold creases when it is opened over the table and if there are “diamonds” at the cross-over points in the fold, the cloth will be rejected.
This fault can sometimes be cured by reducing the number of folds but this is not an option for large cloths or for long banqueting cloths. The solution in many cases is to observe the folding mechanism and to adjust the knife setting so that the fold is more closely controlled and the diamond is either eliminated or reduced to manageable proportions.
When tackling this problem, it is worth checking the moisture content of the fabric. Material which is still slightly damp when it is folded is more likely to reveal undesirable shapes in the fold-crease when unfolded than a perfectly dry item.
Good starching will help the cloth to shed its fold-creases more readily. Use a good quality starch and allow sufficient starching time at the right temperature to allow the starch to build right through the fabric to produce a firm but flexible result. Some rental operators always specify two starching compartments when ordering a continuous batch tunnel washer for this reason.
